Re: Comcast - Significant v4 vs v6 throughput differences, almost stateful.

[Ca By <cb.list6 () gmail com>]

On Thu, Apr 23, 2020 at 8:27 AM Dovid Bender <dovid () telecurve com> wrote:

> We have customers in CT with the same issues. When did this start?

Seems to have started 5 years ago when we ran out of ipv4 and all comers
needed to embrace ipv4 life-support mechanisms

https://www.arin.net/vault/announcements/2015/20150924.html

The e2e ipv6 internet being faster and more robust than life-supported,
bot-ridden, and scarce ipv4 is.... a feature, not a bug.

https://www.internetsociety.org/blog/2015/04/facebook-news-feeds-load-20-40-faster-over-ipv6/




> On Thu, Apr 23, 2020 at 11:07 AM Nick Zurku <nzurku () teraswitch com> wrote:
>
> > Hello all,
> >
> > I would appreciate if someone from Comcast could contact me about this.
> >
> > We’re having serious throughput issues with our AS20326 pushing packets
> > to Comcast over v4. Our transfers are either the full line-speed of the
> > Comcast customer modem, or they’re seemingly capped at 200-300KB/s. This
> > behavior appears to be almost stateful, as if the speed is decided when the
> > connection starts. As long as it starts fast it will remain fast for the
> > length of the transfer and slow if it starts slow. Traces seem reasonable
> > and currently we’ve influenced the path onto GTT both ways. If we prepend
> > and reroute on our side, the same exact issue with happen on another
> > transit provider.
> >
> > This issue does not affect v6 and that is full speed on every attempt.
> > This may be regionalized to the Comcast Pittsburgh market.
> >
> > This is most widely affecting our linux mirror repository server:
> > http://mirror.pit.teraswitch.com/
> > Our colocation customers who are hosting VPN systems are also noticing
> > bottlenecks have started recently for their Comcast employees.
> >
> > --
> > Nick Zurku
> > Systems Engineer
> > TeraSwitch, Inc.
> > nzurku () teraswitch com